Protractor



(No Model.)

M. s. HOY. PROTRAGTOR.

' Patented June 28.1898.

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MARTIN S. HOY, OF VILKINSBURG, PENNSYLVANIA.

PROT RACT-O R.

SPECIFICATION forming part of Letters Patent Noo 606,344, dated June 28, 1898.`

Application led March 18, 1897. Serial No. 628,121. (No model.)

To all whom it may concern:

Be it known that I, MARTINS. HOY, a citizen of the United States, residing at Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in MechanicalDividers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to makel and use the same.

This invention relates to improvements in protracting-bevels, and to this end provides a mechanical divider consisting practically of a quadrant one member or radius of which is provided with a slot, the said quadrant having certain subdivision-s employed in connection with the bevel-stock orpivoted ruler, also carrying subdivisions, all as will be herein` after fully set forth in the specification and the novel 'features specifically pointed out in the claim.

In the accompanying drawings, forming part of this specification, Figure 1 is a plan view of an instrument constructed in accordance with my invention. Fig. 2 is an enlarged detail view ot' a quadrant, showing subdivisions thereon. Fig. 3 is asimilar View of the bevel-stock or ruler.

view through the implement. Fig. 5 is a detail view of the attachment which provides for holding the adjustment of the bevel-stock' or ruler.

Referring to the drawings by numerals and letters, 1 designates a quadrant presenting an angle or square having abla'de 2 and tongue `3, the blade being extended beyond the segment and the tongue having a longitudinal slot 4. Through this slot passes a thumb-screw-5, connecting an attachment 6 and a bevel or ruler 7 in sliding connection with the quadrant, these parts having heads S and 9, respectively,which are provided with segmental slots that are engaged by a thumb-screw 10 for holding these parts adjusted. The blade or tongue 11 of the bevel is secured to the head 8 by screws, leaving a space between the attachment and blade or tongue to receive the tongue of the angle or square of the quadrant. The attachment is provided adjoining its head with guide-rollers 12 12, that bear against the outer edge of the tongue of the l ity of spaces.

-uations from f 1 to 288.

Fig. 4 is a sectional square or angle and hold the said attachment at the proper relative position. f

As shown in the drawings, the blade 2 of the square orangle ofthe quadrant is divided by longitudinal and transverse lines into aplural- For the purpose of illustration we will suppose that the said blade is twentyfour inches inlengthand the transverse lines a cne-twelfthof an inch apart. The said blade is then provided with a scale containing grad- Aprovided with sixteen parallel lines ZJ, extending longitudinally the entire distance. f Thus it is' possible in computing and measuring to return from the point of the blade to the heel, skipping a space in the second line for the miter of the square, and starting with 290, then proceed outward to the point again. This can be proceeded with or continued through the sixteen longitudinal divisions, so that the blade is capable of four thousand six hundred and eight graduations or divisions. The tongue of the angle or Square is marked in the same manner, with the exception that it is but sixteen inches long, and therefore the transverse lines c or graduations would only run to 192 and,coming back to the'heel, would start with 194 on the second and proceed or continue in this manner. The num ber of longitudinal lines l) is'limited to eight spaces, owing to the slot 4, and these spaces or Ygraduations are on the same scale as those on the blade. The blade of the bevel or ruler is marked with lines c f,that are graduated simin lar to those on the blade and the tongue of the square or angle, having sixteen longitudinal lines e and transverse lines orgraduations f, running from l to 400, the second series being graduated from 2 to 800,and so on until all the spaces are iilled. 0n the other side of the square the tongue is pro vided with a scale the marks g of which are one-twelfth of an inch apart and with eight parallel lines 7L,while the blade is marked with spaces or lines i and 7c in the ratio of one to 3.1416. On the same side, which is sixteen-s inch radius from the heel of the square to the trammel-point of each tongue and blade, two radial lilies Z are made, so as to permit the indication of the degrees from 1 to 90 and return, so that the operator can obtain any degree within a quadrant. By providing an The blade is also IOO implement constructed as herein shown and described the bevel or ruler can be brought to the miteroi:` the square and the attachment firmly held in place by the thumb-screw. Then the head or bevel may be brought around to its full capacity, throwing it at` right angles With the blade or squareand" parallel with the tongue thereof. This will give the operator any desired degree in ya quadrant. Now should the operator Wish to f iind the hypotenuse of a right-angle triangle he can do so by setting the bevel or ruler; on tongue of square or angle for one side of the right angle and to a point on blade of square for the other side, the blade or tongue of the bevel or ruler giving the answer.' It will also be apparent that the ruler vand attachments which are applied to the quadrant could be removed, and by providing said attachment with a central opening instead ofthe segmental slot this part of the'ins-trulnen-t could be readily used as a T-square. I

Having thus described `my invention, what I claim .as new, and desire to secure by Letters Patent, is-

The quadrant provided with the slot 4, the blade 2 extending at one end beyond the quadrant, the head 6 secured to one corner of the quadrant and provided with the curved slot at its outer end, and the friction-rollers 12 which bear against the outer edge of the "tongue yof the square or angle, combined with `the bevel or rule 11, the slotted head 8 secured to its inner end, and Which head S cor- 

